Ink cartridge for a writing implement

ABSTRACT

An ink cartridge for a writing implement. The cartridge has a first cylinder defining an ink producing chamber, a first piston in the first cylinder axially movable to suck water into the ink producing chamber, a second cylinder in the first piston containing a concentrated ink, a second piston in the second cylinder axially movable to dispense a metered amount of the concentrated ink into the ink producing chamber whereby both liquids are mixed to produce an ink of desired thickness.

iJited States Patent 1191 Nakata 1 1March 13, 1973 INK CARTRIDGE FOR A WRITING [21] Appl. No.: 145,838

[30] Foreign Application Priority Data April l4, l97l Japan ..46/23582 [52] U.S.CI. ..401/40,401/l34,40l/l76 [51] Int. Cl. ..B43k 5/08, 343k 5/14 [58] Field of Search ..40l/l32-135, 40-43,

[56] References Cited UNITED STATES PATENTS 2,902,978 9/l959 Legnani ..40l/l33 X 1,393,903 10 1921 Perez et al ..401/40 2,097,256 10 1937 Salz I ..401/40 2,243,856 6/1941 Doux ..401 41 x FOREIGN PATENTS 0R APPLICATIONS 287,584 12 1952 Sweden ..401 40 629,622 9 1949 Great Britain ..401 40 Primary ExaminerLawrence Charles Att0rneyKarl W. Flocks [57] ABSTRACT An ink cartridge for a writing implement. The cartridge has a first cylinder defining an ink producing chamber, a first piston in the first cylinder axially movable to suck water into the ink producing chamber, a second cylinder in the first piston containing a concentrated ink, a second piston in the second cylinder axially movable to dispense a metered amount of the concentrated ink into the ink producingchamber whereby both liquids are mixed to produce an ink of desired thickness.

6 Claims, 11 Drawing Figures PATENTEDHARI 31975 SHEET 10F 6 INVENTOR TOSHIHIRO NA KATA BY K14 U 50 K ATTORNEY PATENTEDHAR 1 3197s SHEET 2 OF 6 PATENTEUHARI 3197s SHEET 3 OF 6 FIG. 3A

PATENTEDHARISIQH 3,720,473

SHEET MJF s PIATENTEUHAR'I 3191s sum 5 or e F/G. 5A

PATENTEDHAR 1 31975 SHEET 8 BF 6 FIG. 6A

INK CARTRIDGE FOR A WRITING IMPLEMENT BACKGROUND OF THE INVENTION FIELD OF THE INVENTION The present invention relates to an ink cartridge for a writing implement such as fountain pen and, more particularly, to an ink cartridge containing a quantity of concentrated ink to be thinned with water to produce an ink of normal or desired thickness.

Many of the recent writing implements are of a type that utilizes an ink cartridge. While this kind of writing implement provides some advantages, the writing implements of this kind fall short of satisfaction in that, since a single ink cartridge contains a small quantity of ink, the writing implement is subjected to frequent replacement of a discharged cartridge with another new one.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an improved ink cartridge which enables an associated writing implement to be operable for remarkably longer period of time than by a piece of conventional ink cartridge.

This object is achieved by an ink cartridge according to the present invention which cartridge comprises a first cylinder defining an ink producing chamber having a substantially closed bottom wall, a port in said bottom wall, said cartridge being in communication with a pen core of said writing implement through said port when said cartridge is mounted on said writing implement, a first piston mounted in said first cylinder for axial sliding movement to suck water into said ink producing chamber through said port, a second cylinder provided in said first piston and containing a quantity of concentrated ink, an orifice in the bottom wall of said second cylinder, a second piston mounted in said second cylinder for axial sliding movement to dispense a metered amount of the concentrated ink from said second chamber through said orifice into said ink producing chamber so that the dispensed concentrated ink is mixed with the water in said ink producing chamber to thereby produce an ink of normal thickness, and a check valve normally closing said orifice.

With the above-stated arrangement of the ink cartridge of the present invention, when the quantity of the normal thickness ink produced in the ink producing chamber is completely consumed, a further quantity of normal thickness ink can be produced at any place provided that water isavailable.

In addition, the user can produce an amount of ink of a desired thickness appropriate for an intended application.

Preferably, a small piece of an anti-corrosion materi al such as stainless steel may be placed in the ink producing chamber so as to facilitate immediate mixing of the liquids.

Furthermore, means may be provided to indicate the moved position of the second piston relative to the initial position thereof so that a controlled amount of concentrated ink is dispensed by the forward movement of the second piston.

Other objects, features and advantages of the present invention will be made apparent by the following description with reference to the accompanying drawings illustrating preferred embodiments of the invention.

DESCRIPTION OF DRAWINGS FIG. IA is a partial sectional view of a part of the writing implement which employs an ink cartridge according to one embodiment of the present invention;

FIG. 1B is an enlarged fragmentary perspective view of a part of the ink cartridge shown in FIG. 1;

FIG. 2 is an enlarged sectional view of an ink cartridge according to a modified embodiment of the present invention;

FIG. 3A is an enlarged fragmentary sectional view of another part of the cartridge shown in FIG. 1 illustrating a check valve employed therein;

FIG. 3B is an enlarged perspective view illustrating a valve body of the check valve shown in FIG. 3A;

FIG. 4A is a view similar to FIG. 3A but illustrates a modified check valve;

FIG. 4B is a perspective view illustrating in larger scale the check valve shown in FIG. 4A;

FIG. 5A is a view similar to FIGS. 3A and 4A but illustrates a further modified check valve;

FIG. 5B is a perspective view illustrating in larger scale the check valve shown in FIG. 5A;

FIG. 6A is a view similar to FIGS. 3A, 4A and 5A but illustrates a further modified check valve; and

FIG. 6B is a perspective view illustrating in a larger scale the check valve shown in FIG. 6A with the check valve being shown in inverted position.

DESCRIPTION OF PREFERRED EMBODIMENTS FIGS. IA and 1B illustrate a first embodiment of an ink cartridge of the present invention. As will be seen in FIG. 1, the ink cartridge is generally indicated at I and is shown mounted in a writing implement having pen core 2 and pen nib 3 both of conventional structures.

The ink cartridge includes a first cylinder 10 which serves as an ink producing chamber. A first piston or plunger 11 having a piston ring 111 thereon is slidably mounted in the first cylinder 10 so as to be operative to suck water into the cylinder 10. The first plunger 11 forms with a part thereof a second cylinder 12 which serves as a reservoir or container for a concentrated ink. A second piston 13 is slidably mounted in the second cylinder 12 so as to be operative to pump out a metered quantity of the concentrated ink. The first piston 11 is provided at the forward end with a port or orifice 14 through which the ink is dispensed from the ink reservoir 12 to the ink producing chamber 10. A check valve 15 is mounted on the forward end face of the first piston 11 in opposite relationship to the orifice 14 for the purpose described later. The cartridge 1 is further provided at the forward end of the first cylinder 10 with a connector 16 which is adapted to connect the cartridge to the rear end of the pen core 2 of the writing implement.

The second piston 13 is connected with a threaded piston rod extending rearwardly therefrom and threadably engaging an internal screw thread in an actuator 17 which is mounted rotatably but axially immovably in a stop 18 secured to the rear end portion of the second cylinder 12. Thus, if the actuator 17 is rotated in a direction to move the piston 13 forwardly with respect to the second cylinder 12, a part of the concentrated ink is discharged out of the cylinder 12 into the first cylinder 10. In order to prevent the second piston 13 from being rotated together with the actuator 17 when the same is rotated, a piston ring 131 of either synthetic rubber or a plastic material is mounted on the peripheral surface of the piston 13. The piston ring 131 has such an outer diameter as to tightly and slidably engage with the inner peripheral surface of the cylinder 12 so that the ring 131 is operative to hold by friction the piston 13 against rotation by the actuator 17.

As will be seen in FIG. 1B, the actuator 17 is preferably provided with an indicator 17a on the peripheral surface thereof while the stop 18 is provided with a scale 18a on the rear end face thereof so that not only a metered quantity of ink can be pushed out of the ink reservoir 12 but also the amount of the ink remaining in the reservoir 12 can be known to a user of the writing implement. In addition, a ball of an anti-corrosion material such as stainless steel may preferably be disposed within the ink producing chamber to facilitate immediate stir and mixing of the water and ink within the chamber 10 so that an ink of a desired thickness is produced in the chamber 10.

The operation of the cartridge as described in the above will be described hereunder. The cartridge 1 is first connected by means of the connector 16 to the pen core 2 of a writing implement in conventionally known manner. When the ink within the ink producing chamber 10 has been consumed after the use of the writing implement for a period of time, the watersucking up piston or first piston 11 is once moved to its lowermost dead point and then is pulled up with either the nose of the writing implement or the connector 16 dipped in water to suck water into the ink producing chamber 10. When the piston 11 is moved up, there is produced within the chamber 10 a partial vacuum which not only sucks water into the chamber 10 but also draw the concentrated ink out of the chamber 12 unless the check valve 15 is provided for the reservoir 12 for the concentrated ink. In other words, the check valve 15 is operative the block the orifice 14 to prevent the concentrated ink in the reservoir 12 from being subjected to the suction force by he upward movement of the first piston 11. g 1

Then, the actuator 17 is rotated for a predetermined angle to move the piston 13 axially forwardly relative to the peripheral wall of the cylinder 12 a distance which is required to push out the quantity of concentrated ink necessary for the production of a water-ink mixture or normal thickness ink. The indicator 17a and the scale 18a enable the user to dispense a metered amount of concentrated ink from the reservoir 12 at each time.

The embodiment shown in FIG. 1 has the watersucking up piston 11 which is axially slidable by manually applied force with respect to the peripheral wall of the first cylinder 10. The embodiment shown in FIG. 2 is differentiated from the preceding embodiment in that the second embodiment employs a first piston or plunger 11a formed thereon with external screw threads which are threadably engaged with internal screw treads on a second actuator 20 mounted rotatably but axially immovably on the rear end portion of the first cylinder 10 so that the rotation of the second actuator 20 in a direction will cause the first plunger 11a to move in one axial direction. Piston rings 111a are provided on the plunger 11a for the purpose similar to that of the piston ring 131 in the preceding embodiment. The remaining elements of the instant embodiment are similar to the corresponding elements in the preceding embodiment.

FIGS. 3A through 6B illustrate various modifications of the check valve 15. The check valve 15 shown in FIGS. 3A and 38 includes a ball 30 of an anti-corrosion material such as stainless steel, glass, plastic material or the like. The ball 30 is urged against the outlet opening of the orifice 14 by means of a compression coil spring 31 which is supported by a spring retainer 32 of a similar anti-corrosive material having a shape as shown in FIG. 3B and threadably secured to the forward end of the piston 11.

The check valve 15 shown in FIGS. 4A and 4B includes a small disc 40 of an anti-corrosion and elastic material such as synthetic rubber or plastic material. The disc 40 is secured to one end portion of a leaf spring 41 of stainless steel or the like material which urges the disc 40 against the outlet opening of the orifice 14. The leaf spring 41 extends at the other end into and secured to the forward end portion of the piston 11.

The check valve 15 shown in FIGS. 5A and 5B resembles the check valve 15 shown in FIGS. 3A and 3B but is differentiated therefrom in that the check valve of the FIGS. 5A and 5B embodiment employs a small disc 50 of an anti-corrosion and elastic material such as synthetic rubber or plastic material. The disc 50 is urged against the inlet opening of the orifice 14 by means ofa compression spring 51 which is mounted on and supported by a spring retainer 52 which in turn is rigidly secured to the forward end face of the piston 11.

The check valve 15 shown in FIGS. 6A and 68 employs a ball which is urged against the inlet opening of the orifice 14 by means of a compression coil spring 61 as is in the embodiment shown in FIGS. 3A and 3B. The check valve of the instant embodiment is differentiated therefrom in that a spring retainer 62 for the spring 61 has a shape as shown in FIG. 6B. Namely, the spring retainer 62 has internal screw threads engaged with external screw threads formed on an axial projection on the forward end of the piston 11 while the spring retainer 32 shown in FIGS. 3A and 3B has external screw threads engaged with internal screw threads in an axial bore in the forward end portion of the piston 1 1.

what is claimed is:

1. An ink cartridge for a writing implement having a sleeve and a pen core, said cartridge including a first cylinder defining an ink producing chamber having a substantially closed bottom wall, said first cylinder being of a size that can be loosely received in said sleeve,-a port in said bottom wall, said cartridge being adapted to be detachably connected at said port with said pen core of said writing implement, a plunger having a first part of the outer peripheral surface thereof in axial sliding engagement with the inner peripheral surface of said first cylinder so as to suck a quantity of water into said ink producing chamber through said port, means for effecting axial sliding motion of said plunger, a second cylinder formed in said plunger and containing a quantity of concentrated ink, an orifice in the bottom wall of said second cylinder, a piston in axial sliding engagement with the inner peripheral surface of said second cylinder, a check valve normally closing said orifice and operative in response to the increase in the fluid pressure in said second cylinder to open said orifice for allowing fluid flow communication between said first and second cylinders, said piston having a rearwardly extending piston rod formed with external screw threads thereon, an actuator mounted rotatably but axially immovably on the rear end portion of said second cylinder, said actuator being formed therein with internal screw threads in threadable engagement with said external screw threads on said piston rod so that the rotation of said actuator in one direction relative to said piston rod causes said piston to be axially moved forward with respect to said second cylinder for discharging an amount of said concentrated ink from said second cylinder through said orifice into said ink producing chamber, a scale provided on one of the rear end of said second cylinder and the outer peripheral surface of said actuator, an indicator on the other of said rear end of said second cylinder and the outer peripheral surface of said actuator, said scale and said indicator being cooperative to indicate the angle of rotation of said actuator with respect to said second cylinder whereby a metered amount of said concentrated ink is dispensed from said second cylinder into said ink producing chamber so as to be mixed with said quantity of water in said first cylinder for thereby producing an amount of ink of required thickness.

2. An ink cartridge according to claim 1 in which a small piece of an anti-corrosion material is disposed in said ink producing chamber to facilitate mixing of the dispensed concentrated ink with the water in said ink producing chamber.

3. An ink cartridge according to claim 2, in which said means for effecting sliding motion of said plunger includes a second actuator rotatably but axially immovably mounted on the rear end portion of said first cylinder, said second actuator being formed therein with internal screw threads, said plunger having a second part of the outer peripheral surface thereof offset radially inwardly from said first part, said second part being formed thereon with external screw threads in threadable engagement with said internal screw threads on said second actuator so that the rotation of said second actuator in one direction with respect to said plunger causes said plunger to be axially moved rearwardly with respect to said first cylinder for sucking water into said ink producing chamber.

4. An ink cartridge according to claim 3 in which said check valve comprises a ball member, a coil spring member urging said ball member against outlet opening of said orifice, nd a spring retainer mounted on the forward end of said first piston and holding said spring member against said ball member.

5. An ink cartridge according to claim 3 in which said check valve comprises a disc member and a leaf spring member secured at one end to the forward end of said first piston and supporting and urging at the other end said disc member against the outlet opening of said orifice.

6. An ink cartridge according to claim 3 in which said check valve comprises a disc member, a coil spring member urgin said disc member against the outlet opening of sal orifice, and a spring retainer mounted on the forward end of said first piston and holding said spring member against said disc member.

l IF 

1. An ink cartridge for a writing implement having a sleeve and a pen core, said cartridge including a first cylinder defining an ink producing chamber having a substantially closed bottom wall, said first cylinder being of a size that can be loosely received in said sleeve, a port in said bottom wall, said cartridge being adapted to be detachably connected at said port with said pen core of said writing implement, a plunger having a first part of the outer peripheral surface thereof in axial sliding engagement with the inner peripheral surface of said first cylinder so as to suck a quantity of water into said ink producing chamber through said port, means for effecting axial sliding motion of said plunger, a second cylinder formed in said plunger and containing a quantity of concentrated ink, an orifice in the bottom wall of said second cylinder, a piston in axial sliding engagement with the inner peripheral surface of said second cylinder, a check valve normally closing said orifice and operative in response to the increase in the fluid pressure in said second cylinder to open said orifice for allowing fluid flow communication between said first and second cylinders, said piston having a rearwardly extending piston rod formed with external screw threads thereon, an actuator mounted rotatably but axially immovably on the rear end portion of said second cylinder, said actuator being formed therein with internal screw threads in threadable engagement with said external screw threads on said piston rod so that the rotation of said actuator in one direction relative to said piston rod causes said piston to be axially moved forward with respect to said second cylinder for discharging an amount of said concentrated ink from said second cylinder through said orifice into said ink producing chamber, a scale provided on one of the rear end of said second cylinder and the outer peripheral surface of said actuator, an indicator on the other of said rear end of said second cylinder and the outer peripheral surface of said actuator, said scale and said indicator being cooperative to indicate the angle of rotation of said actuator with respect to said second cylinder whereby a metered amount of said concentrated ink is dispensed from said second cylinder into said ink producing chamber so as to be mixed with said quantity of water in said first cylinder for thereby producing an amount of ink of required thickness.
 1. An ink cartridge for a writing implement having a sleeve and a pen core, said cartridge including a first cylinder defining an ink producing chamber having a substantially closed bottom wall, said first cylinder being of a size that can be loosely received in said sleeve, a port in said bottom wall, said cartridge being adapted to be detachably connected at said port with said pen core of said writing implement, a plunger having a first part of the outer peripheral surface thereof in axial sliding engagement with the inner peripheral surface of said first cylinder so as to suck a quantity of water into said ink producing chamber through said port, means for effecting axial sliding motion of said plunger, a second cylinder formed in said plunger and containing a quantity of concentrated ink, an orifice in the bottom wall of said second cylinder, a piston in axial sliding engagement with the inner peripheral surface of said second cylinder, a check valve normally closing said orifice and operative in response to the increase in the fluid pressure in said second cylinder to open said orifice for allowing fluid flow communication between said first and second cylinders, said piston having a rearwardly extending piston rod formed with external screw threads thereon, an actuator mounted rotatably but axially immovably on the rear end portion of said second cylinder, said actuator being formed therein with internal screw threads in threadable engagement with said external screw threads on said piston rod so that the rotation of said actuator in one direction relative to said piston rod causes said piston to be axially moved forward with respect to said second cylinder for discharging an amount of said concentrated ink from said second cylinder through said orifice into said ink producing chamber, a scale provided on one of the rear end of said second cylinder and the outer peripheral surface of said actuator, an indicator on the other of said rear end of said second cylinder and the outer peripheral surface of said actuator, said scale and said indicator being cooperative to indicate the angle of rotation of said actuator with respect to said second cylinder whereby a metered amount of said concentrated ink is dispensed from said second cylinder into said ink producing chamber so as to be mixed with said quantity of water in said first cylinder for thereby producing an amount of ink of required thickness.
 2. An ink cartridge according to claim 1 in which a small piece of an anti-corrosion material is disposed in said ink producing chamber to facilitate mixing of the dispensed concentrated ink with the water in said ink producing chamber.
 3. An ink cartridge according to claim 2, in Which said means for effecting sliding motion of said plunger includes a second actuator rotatably but axially immovably mounted on the rear end portion of said first cylinder, said second actuator being formed therein with internal screw threads, said plunger having a second part of the outer peripheral surface thereof offset radially inwardly from said first part, said second part being formed thereon with external screw threads in threadable engagement with said internal screw threads on said second actuator so that the rotation of said second actuator in one direction with respect to said plunger causes said plunger to be axially moved rearwardly with respect to said first cylinder for sucking water into said ink producing chamber.
 4. An ink cartridge according to claim 3 in which said check valve comprises a ball member, a coil spring member urging said ball member against outlet opening of said orifice, nd a spring retainer mounted on the forward end of said first piston and holding said spring member against said ball member.
 5. An ink cartridge according to claim 3 in which said check valve comprises a disc member and a leaf spring member secured at one end to the forward end of said first piston and supporting and urging at the other end said disc member against the outlet opening of said orifice. 